CN-115696942-B - Light-emitting device and display device

CN115696942BCN 115696942 BCN115696942 BCN 115696942BCN-115696942-B

Abstract

The disclosure provides a light emitting device and a display device, wherein the light emitting device comprises a plurality of functional layers which are sequentially stacked, the plurality of functional layers comprise an anode, a hole transmission layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transmission layer and a cathode, the light emitting layer comprises at least two light emitting bodies, the different light emitting bodies correspond to sub-pixels with different colors, the light emitting device further comprises at least one energy level transition film layer, the energy level transition film layer is arranged between the at least one light emitting body and the hole transmission layer and/or the hole blocking layer, the energy level band gap difference between two functional film layers adjacent to the energy level transition film layer is larger than a preset value, and the energy level of the energy level transition film layer is between the two functional film layers adjacent to the energy level transition film layer. The light emitting device and the display device provided by the embodiment of the disclosure can improve the light emitting efficiency of the light emitting body so as to solve the problems of poor picture display and the like caused by the difference of the light emitting characteristics of the RGB three sub-pixels.

Inventors

GAO YINGCHANG
WANG HONGLI
Yang meiyi
XIE LINHONG

Assignees

京东方科技集团股份有限公司
成都京东方光电科技有限公司

Dates

Publication Date: 20260508
Application Date: 20221028

Claims (9)

1. A light emitting device comprises a plurality of functional layers which are sequentially stacked, wherein the functional layers comprise an anode, a hole transmission layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transmission layer and a cathode, the light emitting layer comprises at least two light emitting bodies, different light emitting bodies correspond to sub-pixels with different colors, the light emitting device further comprises at least one energy level transition film layer, the energy level transition film layer is arranged between at least one light emitting body and the hole transmission layer and/or the hole blocking layer, the energy level band gap difference between two functional film layers adjacent to the energy level transition film layer is larger than a preset value, the energy level of the energy level transition film layer is between the two functional film layers adjacent to the energy level transition film layer, The material luminous efficiency of at least two luminous bodies is different, wherein the luminous body with the lowest luminous efficiency is a first luminous body, the material of the first luminous body is a fluorescent material, the at least two luminous bodies further comprise a second luminous body and a third luminous body, the material of the second luminous body and the material of the third luminous body are phosphorescent materials, and the energy level transition film layer is only arranged between the first luminous body and the hole transmission layer and/or between the first luminous body and the hole blocking layer.
2. A light-emitting device according to claim 1, wherein, The difference in HOMO energy level band gap between the electron blocking layer and at least one of the light emitters is greater than the predetermined value, at least one of the energy level transition film layers comprises a first energy level transition film layer disposed between the electron blocking layer and the at least one of the light emitters, and the first energy level transition film layer has a HOMO energy level between the at least one of the light emitters and the electron blocking layer.
3. A light-emitting device according to claim 2, wherein, The difference in HOMO energy level band gap between the electron blocking layer and the hole transport layer is less than or equal to the predetermined value.
4. A light-emitting device according to claim 1, wherein, The HOMO energy level band gap difference between the electron blocking layer and the hole transport layer is larger than the preset value, at least one energy level transition film layer comprises a second energy level transition film layer, the second energy level transition film layer is arranged between the electron blocking layer and the hole transport layer, and the LUMO energy level of the second energy level transition film layer is arranged between the hole transport layer and the electron blocking layer.
5. A light-emitting device according to claim 4, wherein, The difference in HOMO level band gap between the electron blocking layer and at least one of the emitters is less than or equal to the predetermined value.
6. A light-emitting device according to any one of claims 1 to 5, wherein, The LUMO energy level band gap difference between at least two of the light emitters and the hole blocking layer is different, wherein the light emitter with the largest LUMO energy level band gap difference between the light emitters and the hole blocking layer is a first light emitter, and at least one of the energy level transition film layers comprises a third energy level transition film layer, which is arranged between the first light emitter and the hole blocking layer.
7. A light-emitting device according to claim 6, wherein, The third energy level transition film layer has a HOMO level greater than the hole blocking layer.
8. A light-emitting device according to claim 1, wherein, The energy level band gap difference between the energy level transition film layer and one of the two adjacent functional film layers is a first difference value, the energy level band gap difference between the energy level transition film layer and the other of the two adjacent functional film layers is a second difference value, and the difference value between the first difference value and the second difference value is smaller than a preset threshold value.
9. A display apparatus comprising the light-emitting device according to any one of claims 1 to 8.

Description

Light-emitting device and display device Technical Field The disclosure relates to the technical field of display, in particular to a light emitting device and a display device. Background AMOLED (Active-matrix organic light-emitting diode, active matrix organic light emitting diode or Active matrix organic light emitting diode) is a display technology, which adopts an autonomous light emitting mode to display different colors through different light emitting body display combinations of RGB. However, the RGB materials are different from each other, and the light emission characteristics are different, which makes it difficult to coordinate them, resulting in poor display of the screen. Disclosure of Invention The embodiment of the disclosure provides a light emitting device and a display device, which can improve the light emitting efficiency of a light emitting body so as to improve the problems of poor picture display and the like caused by the difference of the light emitting characteristics of three RGB sub-pixels. The technical scheme provided by the embodiment of the disclosure is as follows: In a first aspect, an embodiment of the present disclosure provides a light emitting device, including a plurality of functional layers sequentially stacked, where the plurality of functional layers include an anode, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, and a cathode, the light emitting layer includes at least two light emitters, different light emitters correspond to sub-pixels of different colors, and the light emitting device further includes at least one energy level transition film layer disposed between at least one light emitter and the hole transport layer and/or the hole blocking layer, wherein an energy level bandgap difference between two functional film layers adjacent to the energy level transition film layer is greater than a predetermined value, and an energy level of the energy level transition film layer is between two functional film layers adjacent thereto. In an exemplary embodiment, the difference in HOMO level band gap between the electron blocking layer and at least one of the emitters is greater than the predetermined value, at least one of the energy level transition film layers comprises a first energy level transition film layer disposed between the electron blocking layer and the at least one of the emitters, and the first energy level transition film layer HOMO level is intermediate between the at least one of the emitters and the electron blocking layer. Illustratively, the HOMO level bandgap difference between the electron blocking layer and the hole transporting layer is less than or equal to the predetermined value. Illustratively, the HOMO level bandgap difference between the electron blocking layer and the hole transporting layer is greater than the predetermined value, at least one of the energy level transition film layers comprises a second energy level transition film layer disposed between the electron blocking layer and the at least one of the emitters, and the LUMO level of the second energy level transition film layer is intermediate the hole transporting layer and the electron blocking layer. Illustratively, the difference in HOMO level band gap between the electron blocking layer and at least one of the emitters is less than or equal to the predetermined value. In an exemplary embodiment, the light-emitting materials of at least two of the light-emitting materials have different light-emitting efficiencies, wherein the light-emitting material having the lowest light-emitting efficiency is a first light-emitting material, and the energy level transition film layer is disposed between the first light-emitting material and the hole transport layer, and/or between the first light-emitting material and the hole blocking layer. The material of the first illuminant is a fluorescent material. The at least two light emitters further comprise a second light emitter and a third light emitter, wherein the materials of the second light emitter and the third light emitter are phosphorescent materials. In an exemplary embodiment, at least two of the emitters have different LUMO level band gap differences from the hole blocking layer, wherein the emitter having the largest LUMO level band gap difference from the hole blocking layer is a first emitter, and at least one of the energy level transition film layers includes a third energy level transition film layer disposed between the first emitter and the hole blocking layer. Illustratively, the HOMO level of the third level transition film layer is greater than the HOMO level of the hole blocking layer. The energy level bandgap difference between the energy level transition film layer and one of the two adjacent functional film layers is a first difference value, the energy level bandgap difference between the energy level transition film layer